Quantum Physics

Title:
The quantum state cannot be interpreted statistically

Abstract: Quantum states are the key mathematical objects in quantum theory. It is
therefore surprising that physicists have been unable to agree on what a
quantum state represents. There are at least two opposing schools of thought,
each almost as old as quantum theory itself. One is that a pure state is a
physical property of system, much like position and momentum in classical
mechanics. Another is that even a pure state has only a statistical
significance, akin to a probability distribution in statistical mechanics. Here
we show that, given only very mild assumptions, the statistical interpretation
of the quantum state is inconsistent with the predictions of quantum theory.
This result holds even in the presence of small amounts of experimental noise,
and is therefore amenable to experimental test using present or near-future
technology. If the predictions of quantum theory are confirmed, such a test
would show that distinct quantum states must correspond to physically distinct
states of reality.